Protection device for preventing automobile engines from abnormal starts and control method thereof

Abstract

A protection device for preventing automobile engines from abnormal starts comprises automobile batteries ( 10 ), a start motor ( 20 ) and a control circuit ( 30 ) disposed therebetween. The control circuit ( 30 ) comprises a main control unit MCU 1 , a start switch ( 31 ), a start relay ( 321 ) and a power supply relay ( 322 ), the coil of the start relay ( 321 ) being connected to the automobile batteries ( 10 ) through the normally closed contact of the power supply relay ( 322 ). The start relay in the present invention is connected to the batteries rather than directly but through the normally closed contact of the power supply relay. In addition to being controlled by the main control unit, the start relay is also controlled by the power supply relay, thereby providing additional insurance and more effective protection so as to avoid the damage of the start motor due to erroneous actions.

What is claimed is: 
     
       1. A protection device for preventing automobile engines from abnormal starts, comprising
 automobile batteries ( 10 ), 
 a start motor ( 20 ) and 
 a control circuit ( 30 ) disposed therebetween, the control circuit ( 30 ) comprising
 a main control unit MCU 1 , 
 a start switch ( 31 ) connected to the main control unit MCU 1  and at least comprising an ignition gear and a power supply gear, 
 a control relay group comprising:
 at least a start relay ( 321 ) wherein the start relay acts when an ignition switch is turned to the ignition gear, and the automobile starts and 
 a power supply relay ( 322 ), 
 
 wherein the coil of the start relay ( 321 ) is connected to the automobile batteries ( 10 ) through the normally closed contact of the power supply relay ( 322 ) and wherein after the automobile starts, the ignition switch returns to the power supply gear automatically and the normally closed contact of the power supply relay is shut off, as a result, the coil of the start relay is powered off so that the start motor is unable to restart, 
 
 wherein the start switch ( 31 ) comprises the following four gears:
 an ACC power supply gear, 
 a first power supply gear, 
 a second power supply gear and 
 the ignition gear; 
 
 the power supply relay ( 322 ) includes
 a first power supply relay ( 3221 ) and 
 a second power supply relay ( 3222 ),
 the first power supply relay ( 3221 ) and the second power supply relay ( 3222 ) being corresponding to the first power supply gear and the second power supply gear of the start switch ( 31 ), respectively; and 
 the coil of the start relay ( 321 ) is connected to the automobile batteries ( 10 ) through the normally closed contact of the second power supply relay ( 3222 ). 
 
 
 
     
     
       2. The protection device for preventing automobile engines from abnormal starts according to  claim 1 , wherein the control circuit ( 30 ) further comprises a monitoring unit MCU 2  being connected to the main control unit MCU 1 . 
     
     
       3. A method for controlling the protection device for preventing automobile engines from abnormal starts as of  claim 1 , comprising the following steps:
 a) the start relay acts when an ignition is turned to the ignition gear, and the automobile starts; and 
 b) after the automobile starts, the ignition switch returns to the second power supply gear automatically and the normally closed contact of the second power supply relay is shut off, as a result, the coil of the start relay is powered off so that the start motor is unable to restart. 
 
     
     
       4. A protection device for preventing automobile engines from abnormal starts, comprising
 automobile batteries, 
 a start motor and 
 a control circuit connected between the batteries and the start motor and comprising
 a main control unit MCU 1 , 
 a start switch connected to the main control unit MCU 1  and comprising the following four gears:
 an ACC power supply gear, 
 a first power supply gear, 
 a second power supply gear and 
 an ignition gear; 
 
 a control relay group comprising at least a start relay that acts when an ignition is turned to the ignition gear and the automobile starts and a power supply relay comprising:
 a first power supply relay and 
 a second power supply relay wherein the first power supply relay and the second power supply relay correspond to the first power supply gear and the second power supply gear of the start switch respectively and wherein the coil of the start relay is connected to the automobile batteries through the normally closed contact of the power supply relay and wherein, after the automobile starts, the ignition switch returns to the second power supply gear automatically and the normally closed contact of the second power supply relay is shut off and, as a result, the coil of the start relay is powered off so that the start motor is unable to restart. 
 
 
 
     
     
       5. A protection device for preventing automobile engines from abnormal starts, comprising:
 automobile batteries; 
 a start motor; and 
 a control circuit connected between the batteries and the start motor and comprising:
 a main control unit MCU 1 , 
 a monitoring unit MCU 2  connected to the main control unit MCU 1 , 
 a start switch connected to the main control unit MCU 1  and comprising the following four gears:
 an ACC power supply gear, 
 a first power supply gear, 
 a second power supply gear and 
 an ignition gear; and 
 
 a control relay group comprising at least a start relay, and a power supply relay comprising a first power supply relay and a second power supply relay corresponding to the first power supply gear and the second power supply gear of the start switch respectively and wherein the coil of the start relay is connected to the automobile batteries through the normally closed contact of the power supply relay.